Such a door is known from WO 01/309390 (Canadian equivalent 2,421,289). The gas channel on the coke-oven door forms a seal system for preventing the entry and exit of vapors from the coke-oven chamber, so that combustion gases cannot leak from the coke-over chamber and air cannot get into the coke-oven chamber.
It is important that the door seal or door edge form a tight seal around the entire periphery of the gas channel.
It is known that the change in temperature vertically along the door causes the door to bend. There are many suggestions of how to make the seal of the coke-oven door compensate for such deformation. These solutions all have the disadvantage that the spring-loaded seal travel is insufficient to compensate for all deformations.
German 4,103,504 (US equivalent U.S. Pat. No. 5,395,485) describes a coke-oven door where a membrane is pressed by springs against a frame of the coking chamber. The problem with this system is that the membrane must be thick enough that it can withstand the spring forces, that is the membrane must be sufficiently mechanically rigid. The membrane should not be damaged or destroyed by standard cleaning procedures. On the other hand, the membrane must be relatively bendable. These two conflicting requirements are never both met, so that the deformability of the membrane by the springs is insufficient and sealing is unsatisfactory.